Improvement in propellers tor vessels



@anni Citywire.

DOLPHE AUBERT, OFiNOGENT-LE-ROTROU, FRANCE.

Letters Patent No; 94,463, dated September 47, 1869.

IMPRQVEMENT IN' PROPELLERS FOR VESSELS.

-The Schedule referred to in tbeseLetters Patent and making part ox 'che same.

To whom it may concern Be it known that I, ADOLPHE AUBERT, of Nogentle-Rotrou, France, have inventeda certain new and improved Spiro-Gylindrical Propeller for Vessels; and I do hereby declare the following to be a full, clear, and exact description, reference being had to the accompanying drawings. A

rilhe object ot' my invention is to impart to vessels which are moved by propellers either greater power or greater and more uniform speed than can be attained by the employment of the ordinary naked propeller-blade. My improved propeller is constructed of any suitablemetal, such as cast orwrought-iron, steel, copper, bronze, Sac.; and

It essentially consists of the three following elements:

First, a shaft forming the continuation of the driving-shaft, or connected with the latter by a suitable intermediary. g

Second,a helix or blade fixed to this shaft or axis,

making one colnplete turn at its inner side, around the,-

axis, and a half turn around the same at its periphery. Y

Third, a cylinder enc-asin g the blade, and solidly united with or fixed to its periphery by suitable means, and having a diameter equal to its longitudinal axis.

The characteristic feature of my invention lies in the combinationof these three parts, and especially in the fact that the cylindrical casing is solidly united with the helix for the purpose of shielding the latter from the eddies, currents, and other accidental causes which interfere' with the operation of the propeller, and of preventing the loss of power absorbed by the centrifugal force developed at the circumference of the naked blade. By the employment of my improved propeller, the centrifugaly force oi' the helix is confined within the cylindrical casing, and is thus utilized`to -increase the power or speed of the vessel.

The manner in which my invention is or may be carried into eii'eet will be fully understood by reference to the accompanying drawings, in which- Figure 1 represents a transversevertical section of a gropeller made in accordance with my invention, an i Figure 2 is a longitudinal centralsection of the same.

In order to produce the 4best results, the length of the cylinder a should be about e'qual' to its diameter, and the helixb should be so constructed, that while that of it which is fixed to the shaft-'c makes one comshown iu the drawings or in any other suitable manner.

The cylimlrically-cased propeller thus constructed is placed in rear of the vessel below the water-line, so as to be entirely immersed, and is fixed to the end of the revolving shaft c, which is put in motion by the driving-shaft of the engine.

When the propeller is put in motion, its helicoidal acts upon the waterin the usual manner to produce the movement of the vessel. The cylilnieraprevents the violent displacement of the water in a lateral direction, which is occasioned by the centrifugal force developed by the ordinary naked propeller-birdie, by forcing the water taken in at its lower cndto pass out from its opposite end and to be subjected tothe whole pressure of the helix; and -the centrifugal force is thus utilized to increase the movement.

I alu aware that in some instances apropeller-screw has been enclosed within a cylinder, and this, therefore, Ido not claim. The construction of the propeller-blade in'the present case, however, is such that it makes but one complete turn or less at its inner side, and but one half turn or less, around the axis at its periphery, while the cylinder has a diameter equal to its axis; the combination of these parts in this manner producing greatlyiimproved results over what has heretofore been effected.

What I claim, therefore, and desire to secure by Letters Patent, is-

The combination and arrangement, with relation to each other, ofthe propeller-shaft, the helix or blade arranged thereon, and constructed iu the manner speciiied, and the cylinder, with a diameter equal to its length, fixed to and encasiug the ,bla-de, as and for the purposes shown and set forth.

. In testimony whereof,l have signed my name to this specification, before two subscribing witnesses.

A. AUBERT. Witnesses:

A. L xroun, F. Oncor'r. 

